https://www.aavso.org/visual-observing-manual-french
Visual Observing Manual - French | aavso
visual observingmanualfrenchaavso
https://www.amsmeteors.org/ams-programs/visual-observing/
Visual Observing - American Meteor Society
The American Meteor Society, Ltd. is established to inform, encourage, and support the research activities of people who are interested in the field of Meteor...
visual observingamericanmeteorsociety